I did recruit several companions in neketaka (ranger,pally,thief) but when I try to recruit Tekehu the game doesn't close the class select window and it just stuck there.

 

I try everything like going to the inn, get rid of all the group, disable autolevel scale etc, it still wont fix

 

It's crazy to me that a nearly game breaking bug is around after 5 years.

 

Original Steam version of course

That's certainly a new one. Have you tried "verifying the integrity of the game files"?

Do you have any mods installed?

Does it look like the menu is reopening when you click accept?